Make sure onCancel always fires.

mobiscroll.jqm.js calls hide() when the user clicks the underlay, which doesn't
call onCancel.  Fix this so clicking the underlay has the same behavior as clicking
cancel.  Otherwise, there's no way to reliably do things on cancellation, since
you can't tell if it's a cancel or save from onClose (the only event that was being
called before).
Merge pull request #58 from zewt/add-missing-cancel-event

Make sure onCancel always fires.
Merge branch 'master' into development
Adding btn param to onClose event